Flat display devices have many advantages such as thin body, power saving, no radiation and so on, and thus are widely used. The prior flat display device mainly includes a liquid crystal display (LCD) and an organic light-emitting diode (OLED) display device.
A packaging process, such as a frit packaging, is one of processes for preparing the OLED display device. However, in the packaging process, when a temperature gradient and a stress intensity are unevenly distributed as well as that the temperature gradient and the stress intensity do not match a thermal expansion coefficient of material, due to the influence of thermal energy in a laser sealing process, cracks are easily generated on a film under the frit, which may result in breakage of signal lines and thereby causing an abnormal display.